The core component of a light emitting diode (LED) is a semiconductor chip, which comprises two parts, i.e., a P-type semiconductor and an N-type semiconductor. When the two semiconductors are joined to each other, a “PN junction” is formed therebetween. When the current acts on the chip through wires, electrons will be pushed toward the P-type semiconductor region, in which electrons from the N-type semiconductor recombine with holes in the P-type semiconductor and at last emit energy in the form of photons.
If the heat dissipation problem of an LED can not be solved, the LED will have a high junction temperature. According to the Arrhenius law, the service life of the LED may be prolonged twice for each decrease by 10° C. of the junction temperature. Therefore, it is the key for improving the service life of LED to solve the heat dissipation problem of the LED.